[RFC PATCH v3] irqchip: Add support for Tango interrupt controller

On 20/01/2016 17:10, M?ns Rullg?rd wrote:

Marc Zyngier wrote:

quoted

quoted

+	if (of_property_read_u32(node, "reg", &ctl))
+		panic("%s: failed to get reg base", node->name);
+
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	chip->ctl = ctl;
+	chip->base = base;

As I said before, this assumes the outer DT node uses a ranges
property.  Normally reg properties work the same whether they specify an
offset within an outer "ranges" or have a full address directly.  It
would be easy enough to make this work with either, so I don't see any
reason not to.

IIRC, I was told very early in the review process that the ranges prop
was mandatory. Lemme look for it... It was Arnd:

http://thread.gmane.org/gmane.linux.ports.arm.kernel/444131/focus=444207

You are missing a ranges property that describes what address
space these addresses are in.

'ranges;' would be wrong here, as the interrupt controller is
not a bus. If you have no ranges property, the bus is interpreted
as having its own address space with no relation to the parent bus
(e.g. an I2C bus uses addresses that are not memory mapped).

Just list the addresses that are actually decoded by child
devices here.

Did I misunderstand?

Regards.